首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4398篇
  免费   279篇
  国内免费   15篇
耳鼻咽喉   52篇
儿科学   412篇
妇产科学   64篇
基础医学   416篇
口腔科学   84篇
临床医学   293篇
内科学   1092篇
皮肤病学   72篇
神经病学   240篇
特种医学   126篇
外科学   724篇
综合类   120篇
一般理论   3篇
预防医学   206篇
眼科学   147篇
药学   251篇
中国医学   24篇
肿瘤学   366篇
  2023年   31篇
  2022年   70篇
  2021年   165篇
  2020年   105篇
  2019年   119篇
  2018年   146篇
  2017年   115篇
  2016年   124篇
  2015年   136篇
  2014年   203篇
  2013年   273篇
  2012年   327篇
  2011年   309篇
  2010年   171篇
  2009年   177篇
  2008年   292篇
  2007年   211篇
  2006年   208篇
  2005年   190篇
  2004年   161篇
  2003年   129篇
  2002年   102篇
  2001年   93篇
  2000年   103篇
  1999年   64篇
  1998年   41篇
  1997年   27篇
  1996年   21篇
  1995年   10篇
  1994年   17篇
  1993年   26篇
  1992年   41篇
  1991年   51篇
  1990年   39篇
  1989年   51篇
  1988年   41篇
  1987年   24篇
  1986年   39篇
  1985年   29篇
  1984年   22篇
  1983年   13篇
  1981年   17篇
  1979年   22篇
  1978年   9篇
  1976年   12篇
  1975年   12篇
  1973年   12篇
  1971年   9篇
  1970年   10篇
  1969年   18篇
排序方式: 共有4692条查询结果,搜索用时 15 毫秒
161.
Archives of Gynecology and Obstetrics - Studies have reported a surge in the prevalence of obesity among various demographic groups including pregnant women in the U.S. Given the association...  相似文献   
162.
163.
Neuronal mitochondrial dysfunction increases inflammatory mediators and leads to free radical generation and anti-oxidant enzymatic alterations,which are major neuropathological hallmarks responsible for autism.Mitochondrial dysfunction in autism is associated with decreased ATP levels due to reduced levels of cyclic adenosine monophosphate.Rat models of autism were established by intracerebroventricular injection of propionic acid.These rat models had memory dysfunction,decreased muscle coordination and gait imbalance.Biochemical estimation of propionic acid-treated rats showed changes in enzyme activity in neuronal mitochondrial electron transport chain complexes and increases in pro-inflammatory cytokines,oxidative stress and lipid biomarkers.Oral administration of 10,20 and 30 mg/kg adenylate cyclase activator forskolin for 15 days reversed these changes in a dose-dependent manner.These findings suggest that forskolin can alleviate neuronal mitochondrial dysfunction and improve neurological symptoms of rats with autism.This study was approved by the RITS/IAEC,SIRSA,HARYANA on March 3,2014(approval No.RITS/IAEC/2014/03/03).  相似文献   
164.
165.
Griscelli syndrome 2 is a rare autosomal recessive disorder of pigmentary dilution of hair, skin, splenohepatomegaly, pancytopenia, immune and neurologic dysfunction. Clinical course is characterized by recurrent infection triggered by uncontrolled T-lymphocyte and macrophage activation, called hemophagocytic syndrome. Since the primary presentation is with depigmented hair, we attempt to highlight diagnostic difficulties in such cases in developing countries like ours where pigmentary changes in hair and skin are commonly attributed to severe malnutrition. We also evaluated phenotype of all 10 cases of genotype (c.C550T; p.R184X), collected from published literature worldwide and emphasize the potential role of above mutation as hotspot in Southeast Asian region.  相似文献   
166.
Introduction: The diagnosis of amyloidosis requires histological confirmation of Congo-red (CR) deposits. The tissue source is preferably fat aspiration and/or bone marrow (BM) biopsy, but at times organ biopsy is required.

Methods: We studied 612 patients with systemic immunoglobulin light chain amyloidosis to characterise the tissues used to establish the diagnosis.

Results: The median number of tissue samples was 3. About 95% of BM biopsies were stained for CR, while 79% of patients had fat aspiration CR-stained. CR stain sensitivity was 69% in BM, 75% in fat aspiration and 89% for both sources combined. In comparison, CR sensitivity was 97–100% for heart, renal and liver biopsies. About 42% of patients with renal involvement, 21% of patients with liver involvement and 13% of patients with heart involvement underwent organ biopsy, when a less invasive biopsy would have established the diagnosis. Predictors for the requirement for organ biopsy were male sex, limited organ involvement and lack of fat aspiration.

Discussion: Fat aspiration is underutilised for histologic confirmation of amyloidosis. A high rate of organ biopsies represents a failure to recognise the disease. Early awareness of amyloidosis in patients with organ dysfunction may lead to more judicious use of organ biopsies in this disease.

  • Key messages
  • Fat pad aspiration is underutilised to establish the diagnosis of amyloidosis.

  • Bone marrow and fat pad aspiration obviates the need for invasive biopsies.

  • The excessive use of organ biopsy in AL amyloidosis reflects failure to recognise the disease early in its course.

  相似文献   
167.
168.
BACKGROUND: The contribution of Chlamydia spp in respiratory tract infections in paediatric population from India has not been studied in detail. METHODS: Sixty children under five years of age who were admitted with acute lower respiratory tract infection during a one year period were investigated for Chlamydial aetiology of respiratory infection. Diagnosis was based on antigen detection by direct immunofluorescence (DIF) in throat swab along with anti-Chlamydial immunoglobulin G (IgG) antibody demonstration by solid phase enzyme immunoassay (EIA). RESULTS: Chlamydia spp antigen was detected in seven (11.6%) cases, C. pneumoniae in six (10%) and C. trachoniatis in one (1.6%). Chlamydia spp IgG antibody in serum was demonstrated in 24 (40%) cases, of which C. pneumoniae IgG was denconstrated in 18 (30%) cases. Taking the criteria of antigen detection (n=7) and high IgG antibody titre of > or = 1:512 (n=5) for a positive case, 12 (20%) children were found to be suffering from recent Chlamydial infection. CONCLUSION: Chlamydia spp plays a significant role in respiratory tract infections in Indian paediatric population. Diagnostic procedure like antigen detection in throat swab is rapid, less cumbersome and feasible and should be more widely used along with antibody demonstration to determine the aetiological agent early in the course of illness.  相似文献   
169.
Traumatic brain injury (TBI) is among the leading causes of death and disability all over the globe. TBI is also commonly associated with clinical sequelae of posttraumatic depression, and reports of other subsequent affective distress are common. Similarly, posttraumatic changes in chemoreceptive sensory functions, primarily due to coup-contrecoup injury induced shearing of the olfactory nerve fibers, leading to anosmia and ageusia are also well documented in the literature. However, the current literature is limited in addressing the intersections between said variables. The aim of this study was to provide a focused narrative review of the literature, to address these intersections found in clinical sequelae of TBI. As chemoreceptive sensory deficits are also linked to significant affective distress of their own, this review addresses the bidirectionality between sensory deficit and affective distress. Prevalence, demographics, mechanisms, and clinical implications are presented. Previous research is presented and discussed, in an effort to highlight the importance of consideration for all factors in TBI patient care and future research.  相似文献   
170.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号